CEN13FA182

NTSB accident investigation · Aero Commander 500B · Broomfield, CO · March 1, 2013

Accident · Minor injuriesField investigationFinal report
Date
March 1, 2013, 15:45 local (22:45 UTC)
Place
Broomfield, CO
Injuries
2 minor
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N93AAAero Commander 500B
Defining event
Initial climb: Loss of engine power (partial)
Weather
Visual (VMC) · Day
Status
Completed · report December 11, 2013
Report
Approved by Office Director
NTSB office
Central Region
Parties
FAA Flight Standards District Office
FAA report
20130301003439A
Case key
86335

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

Loss of engine power due to fuel exhaustion. Contributing to the accident was the failure of the fuel gauge to indicate the actual amount of fuel on board the airplane and the design of the airplane's fuel system, which precluded a visual confirmation of the fuel level.

Findings · 4

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Fuel systemAircraft › Aircraft systems · DesignAero Commander 500-B: 1 caseAll aircraft: 181 casesProbable cause
Fuel system: fuel quantity sensorAircraft › Aircraft systems · MalfunctionAero Commander 500-B: 1 caseAll aircraft: 10 casesProbable cause
Fluids: fuelAircraft › Fluids/misc hardware · Fluid levelAero Commander 500-B: 5 casesAll aircraft: 1,695 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The pilot stated that, during the preflight inspection of the airplane, he checked the fuel gauge, and it indicated 65 gallons. Due to the design of the fuel system, it is not possible to visually check the fuel level to confirm that the fuel gauge indication is accurate. During takeoff and as he reduced power for enroute climb, the left engine began to surge and lose power. He immediately turned left back toward the airport and contacted the control tower to advise that he was making a single-engine, straight-in approach to land. When he lowered the landing gear, the right engine began to surge and lose power. Subsequently, the pilot declared an emergency, and, realizing he had insufficient engine power and altitude to return to the airport, he retracted the landing gear and made a no-flap, gear-up landing on a nearby golf course. Postaccident application of battery power to the airplane confirmed that the fuel gauge indicated 65 gallons; however, when the airplane's fuel system was drained, only about 1/2 gallon of fuel was recovered. Thus, the engines lost power due to fuel exhaustion.

Factual narrative

The pilot said that when he preflighted the airplane, the fuel gauge indicated 65 gallons. Due to the design of the fuel system, it is not possible to visually check the fuel level unless all tanks are completely full. An FAA inspector applied battery power to the airplane post accident and the fuel gauges displayed 65 gallons of fuel. According to the salvage company that recovered the airplane, approximately ½-gallon of 100LL aviation gasoline was drained from the fuel system. The following are excerpts from Section V of the Aero Commander 500B Maintenance Manual: "Fuel is contained in five rubberized fuel bladders, two of which are located in each wing, inboard of the nacelles, and one in the center wing section above the baggage compartment. The five cells have a total capacity of 150-159 U.S. gallons and are interconnected by two-inch diameter tubes to ensure adequate fuel flow from the wing cells to the center cell. All cells are filled through the fuel fill port located on top of the right wing above the forward fuel cell. "The fuel quantity indicating system is comprised of an indicating gage, mounted on the instrument panel… with a dial to indicate the quantity of fuel in the fuel cells. The fuel quantity gage dial is marked from E (empty) to 135 U.S. gallons. Fuel cell capacity above 135 gallons is not indicated." N93AA, serial number 500B-1296-111, was manufactured by the Aero Commander Corporation in 1964. It was powered by two Lycoming IO-540-E1B5 fuel-injected engines, rated at 290 horsepower each. According to the aircraft's maintenance records, an annual inspection was done on February 13, 2013, at a total airframe time of 10,020.6 hours. The Hobbs meter read 586.7 hours. At that time, the left engine was replaced by an overhauled engine (serial number L-8807-48). The engine had accrued 5,391.0 total hours before overhaul. The right engine, serial number L-11118-48, had been overhauled on April 18, 2012. Total hours prior to overhaul were not given, but it had accrued 167.6 hours since overhaul. Both propellers were Hartzell models HC-A3VK-2B. The left propeller (serial number BJ74) and the right propeller (serial number BJ252) had accrued 167.6 hours since overhaul. Total hours on the propellers were not given. On March 1, 2013, about 1545 mountain standard time, an Aero Commander 500B, N93AA, lost power on both engines shortly after takeoff, and the pilot made a gear-up forced landing on a golf course fairway near Broomfield, Colorado. The airline transport pilot and one passenger received minor injuries. The airplane was substantially damaged. The airplane was registered to and operated by American East Airways Corporation under the provisions of 14 Code of Federal Regulations Part 91 as a test flight. Visual meteorological conditions prevailed for the local flight, which operated without a flight plan. The flight originated from Rocky Mountain Metropolitan Airport (KBJC), Broomfield, about 1540. The pilot said that during theairplane preflight, the fuel gauge indicated 65 gallons, but the design of the fuel system precluded a visual inspection of the fuel level. The pilot said he took off on what was to be a test flight after the installation of the left engine. Shortly after reducing to climb power, the left engine began to surge and lose power. The pilot made an immediate left turn back towards the airport and contacted the control tower to advise he was making a single-engine straight-in landing approach. When he lowered the landing gear, the right engine began to surge and lose power. The pilot declared an emergency. Realizing he had insufficient engine power and altitude to return to KBJC, he retracted the landing gear and made a no-flap gear-up landing on the Omni Interlocken Golf Course. Weather recorded by the KBJC AWOS (Automated Weather Observation Station) at 1549 was as follows: Wind, calm; visibility, 40 statute miles; sky condition, 9,000 feet scattered clouds, ceiling 22,000 feet, broken clouds; temperature, 7 degrees Celsius (C.); dew point, -8 degrees C.; altimeter, 30.24 inches of mercury. The pilot, age 69, held an airline transport pilot certificate with a multiengine land rating, and commercial privileges in airplanes single-engine land/sea and glider ratings. He was type rated in the Boeing 737 and a Dornier Alpha Jet. He also held a flight instructor certificate with airplane single/multiengine and instrument ratings, and a ground instructor certificate with an advanced rating. His first class airman medical certificate, dated December 3, 2012, contained restrictions for corrective lenses to be worn for distant vision, and possess glasses for near and intermediate vision. The pilot estimated he had logged more than 15,000 total flight time, of which more than 414 hours were accrued in the Aero Commander. The fuselage structure, forward of wing attach point, was bent upwards and there was vertical deformation throughout the length of the fuselage, particularly the lower portion. The outer 3 feet of the left wing was crushed back to the spar, and the left propeller blades were bent.

Aircraft

Registration
N93AA
Reported as
Aero Commander 500B
Category
Airplane
Serial number
500B-1296-111
Airframe hours
10,021
Engine
Lycoming IO-540-E1B5, 290 horsepower, reciprocating
Damage
Substantial damage
Flight
Flight test · Part 91
Operator
American East Airways Corporation, doing business as Houston Air
Registered owner
American East Airways Corporation
Airworthiness certificate
Standard, Normal
Last inspection
Annual · February 13, 2013
Departed
KBKC · Broomfield, CO
Destination
KBKC · Broomfield, CO
Airport
KBJC · Rocky Mountain Metropolitan

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
69
Injuries
Minor
Certificates
Commercial, Airline transport
Airplane ratings
Multi-engine land, Single-engine sea, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, With waivers/limitations
Last flight review
February 8, 2013
Seat
Left
Flight hours
15,000 total · 414 in this make and model · 14,000 as pilot in command · 34 in the last 90 days · 29 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
40 statute miles
Lowest ceiling
22,000 ft broken
Temperature
45 °F, dew point 18 °F
Altimeter
30.23 inHg
Observed at
KBJC, 25 nm away

Docket · 9

The files NTSB released with the investigation on September 6, 2013, on NTSB’s docket system: statements, records, photos and specialists’ reports. 10.5 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.